Quick question: Do you want the player to be able to carry multiple of these? Because for most key items, you can only carry one at a time, but it's possible to let the player carry multiple. Doors are just going to work differently (with single carry key items, you can set the 'key' function on the door, but multi-carry keys don't register like that).
Edit: Also, one of the items (a helmet) has multiple parts. I'm not sure if that's possible with an item.
Edit2: Here they are as functional key items (except the multipart helmet). Do you want them to display some specific name. Right now they're all just generic "shield," "sword," "armor." Do you want them to be more specific like "Centurion's Helmet" or something?